I've started an own Website (pure hobby) that applies the career ranking criteria of sumo, Japan's national sport, to grand slam tennis. The highest rank that can be obtained in sumo is Yokozuna, and a Yokozuna promotion typically requires winning back-to-back Grand (Slam) tournaments. Nadal jumped this hurdle at Wimbledon, he is the 15th player in the open ear who did. The other 14 are listed in the table linked up here.

27 male players reached the second highest rank, Ozeki, in their careers, Nadal just waved these bye-bye. There are also 15 female Yokozuna and 28 female career-high Ozeki, and many players at two somewhat lesser championship ranks (Sekiwake and Komosubi).